Xylastriasan A,a new cytochalasan from the fungus Xylaria striata

Xylastriasan A (1), a new cytochalasan alkaloid with a rare 5/6/6/5/6 pentacyclic skeleton, and ergosterol (2) were isolated from the ethanol extract of fruiting bodies of the fungus Xylaria striata. Their structures were determined by analysis of their spectroscopic data. Compound 1 exhibited weak cytotoxic activity against HEPG2, B16 and A549 cell lines with IC₅₀ values of 93.61, 85.61 and 91.58 μM, respectively. Ergosterol (2) potentiated pentobarbital-induced sleep by not only increasing the number of falling asleep and prolonging sleeping time but also reducing sleep latency at a dosage of 5 mg/kg.     

A new antifungal and antiprotozoal bibenzyl derivative from Gavilea lutea

A new bibenzyl derivative (4), together with two glycosylated flavonoids (1 and 2), batatasin III (3) and the phenanthrene isohircinol (5) were isolated from the aerial parts of Gavilea lutea. Their structures were elucidated on the basis of spectroscopic studies including 1D and 2D NMR, UV, IR and HRESIMS. All isolated compounds were evaluated for their antifungal activity towards Candida albicans. The new compound 4 showed inhibitory activity with a MIQ of 50 μg. In addition, compound 4 exhibited a selective activity (IC₅₀ = 2.3 μg/mL) against Leishmania donovani.     

Daphniphyllum alkaloids with cytotoxic activity from Daphniphyllum angustifolium

A new Daphniphyllum alkaloid, daphnezomine W (1), together with four known ones, were isolated from the stems of Daphniphyllum angustifolium Hutch. Their structures were elucidated by spectroscopic methods and comparing with the literature data. Compound 1 was a new daphnezomine L-type alkaloid and exhibited moderate cytotoxic activity against Hela cell line with IC₅₀ of 16.0 μg/mL. A plausible biosynthetic pathway of 1 was also proposed.     

A syringic acid derivative and two iridoid glycosides from the roots of Stachys geobombycis and their antioxidant properties

A new derivative of syringic acid, stageobester A (1) and two iridoid glycosides which including a new one, stageoboside A (2), were isolated from the roots of Stachys geobombycis. Their structures were elucidated on the basis of spectroscopic methods, including extensive NMR and MS spectra. In addition, all the isolates were tested for their antioxidant capacity. Compounds 1 and 2 showed moderate antioxidant activities against DPPH radical, with IC₅₀ values of 113.33 ± 1.53 and 40.33 ± 2.08 mg/L, respectively.     

A new antimicrobial and radical-scavenging glycoside from Paullinia pinnata var. cameroonensis

A new glycoside, pinnatoside A (1), together with two known compounds (2 and 3), were isolated from the stems of Paullinia pinnata. Their structures were elucidated on the basis of extensive spectroscopic analysis and chemical methods. Compound 1 showed significant antibacterial activity with a minimum inhibitory concentration (MIC) value of 1.56 μg/mL against Escherichia coli, and 2 displayed significant antibacterial activity with a MIC value of 1.56 μg/mL against Enterobacter aerogenes and E. coli. Equally, compound 1 exhibited the best radical-scavenging activity (RSa₅₀ = 25.07 ± 0.49 μg/mL).     

Argininosecologanin,a secoiridoid-derived guanidine alkaloid from the roots of Lonicera insularis

A new secoiridoid-derived guanidine alkaloid, argininosecologanin (1), along with 12 known iridoids and secoiridoids (2–13), was isolated from the roots of Lonicera insularis. The structures of the isolated compounds were established by the spectroscopic analysis and comparison of their spectral data with previously reported data. Compound 1 was assigned as the first secoiridoid-derived guanidine alkaloid isolated as a natural product. A plausible biogenetic pathway for 1 is suggested based on its structural similarity to (E)-aldosecologanin (4).     

A new cytotoxic biflavonoid from the rhizome of Wikstroemia indica

One new chalcone-flavone biflavonoid, 3′-hydroxydaphnodorin A (1), together with 12 known biflavonoids (2–13), was isolated from the rhizome of Wikstroemia indica. Their structures were established on the basis of extensive spectroscopic methods. Eight isolated compounds 1–3, 6, 7, 9, 12 and 13 were evaluated for their cytotoxic activities against cancer-derived cell lines Hep3B, HepG2 and CNE2, and 1 was found to possess moderate cytotoxicity against HepG2 and CNE2 cell lines, with IC₅₀ values of 65.5 ± 11.4 and 53.6 ± 10.1 μM, respectively.     

A new abietane diterpenoid from the roots of Tripterygium regelii

A new abietane diterpenoid, tripterregeline A (1), together with six known diterpenoids (2–7), were isolated from the roots of Tripterygium regelii. The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparison with data reported in the literature. All isolated compounds were evaluated for their cytotoxicities against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 in vitro. Compounds 1–7 showed significant inhibitory effects against various human cancer cell lines with IC₅₀ values ranging from 0.58 to 21.06 μM.     

Bioactive furanocoumarins from the stems and leaves of Clausena hainanensis

A new furanocoumarin, clauhainanin A (1), together with seven known furanocoumarins (2–8), were isolated from the stems and leaves of Clausena hainanensis. The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with data reported in the literature. All known compounds (2–8) were isolated from C. hainanensis for the first time. All isolated compounds were evaluated for their cytotoxicities against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 in vitro. Compounds 1–8 exhibited significant inhibitory effects with IC₅₀ values ranging from 1.36 to 18.96 μM.     

New alkaloids from the leaves of Evodia rutaecarpa

One new indole alkaloid (1) and one new indole alkaloidal glycoside (2), together with nine known alkaloids (3–11), were isolated from the leaves of Evodia rutaecarpa. Their structures were determined on the basis of spectroscopic and chemical methods. Compound 4 exhibited potent activity against Pseudomonas aeruginosa with an MIC value of 7.13 μg/ml.     

Three new biflavonoids from the branches and leaves of Cephalotaxus oliveri and their antioxidant activity

Three new biflavonoids, named oliveriflavones A-C (1–3), together with two known flavonoids (quercetin (4) and rutin (5)), were isolated from the endangered plant Cephalotaxus oliveri. The chemical structures of these compounds were elucidated by comprehensive spectroscopic methods including NMR, HRESIMS, IR, UV, and CD spectra. Compounds 1–5 were first isolated from the genus Cephalotaxus. All the compounds were tested for their antioxidant activity. Compounds 4 and 5 showed excellent activity with IC₅₀ values of 0.03 ± 0.06 μM and 0.02 ± 0.10 μM, respectively.     

New lignan from the rattan stems of Schisandra chinensis

A new lignan named schilignan F (1), together with twelve known ones (2–13), were isolated from the rattan stems of Schisandra chinensis. Their chemical structures were elucidated by spectroscopic methods including one and two-dimensional NMR spectra referring to the literatures as well as high-resolution mass spectrometric analysis. All compounds were evaluated for their cytotoxicities against human Hela cancer cell lines in vitro. The results showed that compounds 2, 6 and 8 exhibited weak cytotoxic activity with IC₅₀ values of 30.6, 86.3 and 41.0 μM, and cisplatin showed cytotoxic activity with IC₅₀ value of 27.3 μM.     

A new 3-alkylpyridine alkaloid from the marine sponge Haliclona sp. and its cytotoxic activity

A new alkaloid, 3-dodecyl pyridine containing a terminal cyano group (1), was isolated from the methanol extract of an Indonesia marine sponge Haliclona sp. Its chemical structure was determined by a combination of spectroscopic methods, including 1D and 2D NMR. Bioassay results indicated that compound 1 had moderate cytotoxity against tumour cell lines A549, MCF-7 and Hela with IC₅₀ values of 41.8, 48.4 and 33.2 μM, respectively.     

Two new benzophenones and one new natural amide alkaloid isolated from a mangrove-derived Fungus Penicillium citrinum

Two new compounds penibenzophenones A-B (1–2), and the synthetic α,β-unsaturated amide alkaloid (E)-tert-butyl(3-cinnamamidopropyl)carbamate (4), newly identified as a natural product, alone with three known ones (3, 5–6) were isolated from the EtOAc extract of the endophytic fungus Penicillium citrinum HL-5126 isolated from the mangrove Bruguiera sexangula var. rhynchopetala collected in the South China Sea. Compound 1 was a chlorinated benzophenone. The structures of 1–6 were elucidated by extensive NMR spectral interpretation, MS data and X-ray analysis. The new compound 2 displayed cytotoxic activity against human A549 cell lines with an IC₅₀ value of 15.7 μg/mL, and 1 showed antibacterial activity against Staphylococcus aureus with a MIC value of 20 μg/mL.     

Acetylcholinesterase inhibitory active metabolites from the endophytic fungus Colletotrichum sp. YMF432

An endophytic fungus, Chaetomium sp. YMF432, was isolated from Huperzia serrata (Thunb. ex Murray) Trev. and subjected to phytochemical investigation based on its special environment. From the extracts of fermentation solid of strain YMF 432, eight compounds including 1-O-methylemodin (1), 5-methoxy-2-methyl-3-tricosyl-1,4-benzoquinone (2), 4,8-dihydroxy-1-tetralone (3), (3β,5α,6α, 22E)-3-hydroxy-5,6-epoxy-7-one-8(14),22-dien-ergosta (4), ergosta-4,6,8(14),22-tetraen-3-one (5), β-sitostenone (6), β-sitosterol (7) and (22E,24R)-ergosta-5,7,22 -trien-3β-ol (8) were obtained. Their structures were elucidated on the basis of their spectroscopic data. These compounds were evaluated for acetylcholinesterase inhibitory activities in vitro. Compounds 1, 2, and 4 showed moderate acetylcholinesterase inhibitory activities (IC₅₀ from 37.7 ± 1.5 to 370.0 ± 2.9 μM).     

Noralashinol A,a new norlignan from stem barks of Syringa pinnatifolia

One new norlignan, namely noralashinol A (1), one known analogue (2), together with seven known lignans (3–9) were isolated from the stem barks of Syringa pinnatifolia. Their structures were elucidated extensively by spectroscopic methods, including mass spectrometry and 1D and 2D NMR spectroscopies. Compound 8 significantly inhibited NO production in LPS-induced BV-2 murine microglia cells with its IC₅₀ value of 20.7 μM, compared to a positive control quercetin with its IC₅₀ value of 15.3 μM.     

A new diterpenoid alkaloid from Aconitum hemsleyanum

Abstract

A new C₁₉-diterpenoid alkaloid named hemsleyaline (1), along with fourteen known alkaloids (2-15), were isolated from the roots of Aconitum hemsleyanum Pritz. (Ranunculaceae), a herbal medicine in southwest China. Their structures were established on the basis of extensive spectroscopic analyses. Compound 1 showed mild cholinesterase inhibitory effect with IC₅₀ value of 471?±?9?μM.     

A new depsidone derivative from the leaves of Garcinia polyantha

One new depsidone, polyanthadepsidone A (1), together with four known compounds were isolated from the dichloromethane extract of the leaves of Garcinia polyantha. The structures of all compounds were determined by comprehensive analyses of their 1D and 2D NMR and EI mass spectral data. All the isolates exhibited suppressive effect on phagocytosis response upon activation with serum opsonised zymosan in the IC₅₀ range of 4.5–23.80 μM, tested in vitro for oxidative burst studies of whole blood.     

A new polyoxygenated cyclohexene derivative from Artabotrys hainanensis

A new polyoxygenated cyclohexene derivative, artahainanol A (1), together with three known analogues (2–4), was isolated from the stems and leaves of Artabotrys hainanensis. Among them, 1 is an unusual polyoxygenated cyclohexene containing 14 carbon atoms on the carbon skeleton. All known compounds (2–4) were isolated from the genus Artabotrys for the first time. The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with data reported in the literature. All isolated compounds were evaluated for their cytotoxicities against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 in vitro. Compounds 1–4 showed significant inhibitory effects against various human cancer cell lines with IC₅₀ values ranging from 2.68 to 18.32 μM.     

Pheophytin analogues from the medicinal lichen Usnea diffracta

A new pheophytin, (13²S, 17S, 18S)-13²-hydroxy-20-chloro-ethylpheophorbide a (3), along with two known analogues (1–2) were isolated from the lichen Usnea diffracta Vainio (Parmeliaceae). Among them, compound 3 was a rare C-20-chloro type pheophytin obtained from lichens. Their structures were elucidated by extensive spectroscopic analysis, and all the compounds were obtained for the first time from U. diffracta. Compounds (1–3) were evaluated for their xanthine oxidase (XO) inhibitory activities in vitro, and the results showed that 1–3 possessed significant enzyme inhibitory actions with IC₅₀ values of 46.9 ± 3.8, 75.9 ± 7.4 and 42.1 ± 1.7 μg/mL, respectively.